气候特点概述

<正>2014年4—6月,江西省总的气候特点是:气温偏高、降水略多、日照偏少。主要天气气候事件:4—6月中南部气温异常偏高,5月暴雨、强降水过程频繁,导致局部灾情较重。1气候概况1.1气温。4—6月全省平均气温为22.9℃,较常年同期平均偏高0.7℃,为历史同期第6高位。4、5、6月全省平均气温分别为19.6、22.7、26.3℃,较常年同期相比,4、6月偏高1.6、0.5℃,5月持平。     

基于GAMIT的GPS数据处理系统设计与气象应用

介绍了基于GAMIT的导航卫星气象学GPSMET(Global Positioning System METeorology)数据处理的设计内容和实现方法,并且通过解算实时数据验证了该系统设计的合理性和功能的可用性。该系统设计主要包括数据接收与处理、数据处理的核心模块、系统监控和产品应用等模块。系统通过接收原始的观测数据,经过数据处理后,反演出可降水量PWV(Precipitable Water Vapor)值,同时系统还可以提供单站水汽变化曲线产品、多站水汽产品和全省水汽分布图,可以给预报员直接应用于天气预报分析。     

Sediment records of environmental changes in the south end of the Zhejiang-Fujian coastal mud area during the past 100 years

Previous studies carried out in the East China Sea （ECS） mud area focused on long-term environmental changes in sedimentary records during the Holoeene, especially during the mid-Holocene high-stand water levels period. These results indicate that sensitive grain size groups can be used as a sedimentary proxy to reconstruct the evolution of the East Asian Winter Monsoon （EAWM）. The studies have been carried out mainly in the northern and middle portions of the Zhejiang-Fujian coastal mud, however, similar research in the southern portion and the comparison between sedimentary proxy and modern measured data of EAWM are lacking. In this paper, we focused on a sedimentary record of the past 100 years with an enhanced resolution of 1.8 years. Investigations of the southern end of the Zhejiang-Fujian coastal mud area were conducted on the basis of 21~Pb chronology, grain-size analysis and chemical element analysis. The correspondence between the mean grain size （Mz） of sediment sensitive grain size and the measured EAWM was confirmed for the first time. We found that during the recent 100 years, the variation of the mean grain size of the sensitive population in the southern portion of the Zhejiang-Fujian mud was mainly controlled by the EAWM intensity changes; and not directly related to changes in the sediment discharge from Datong station of the Changjiang River （DTSD）. Finally, recent changes in the content of heavy metals in study area reflect the impact of human activities on the environment.     

Statistical Downscaling of FGOALS-s2 Projected Precipitation in Eastern China

A statistical regression downscaling method was used to project future changes in precipitation over eastern China based on Phase 5 of the Coupled Model Intercomparison Project （CMIPS） the Representative Concentration Pathway （RCP） scenarios simulated by the second spectral version of the Flexible Global Ocean- Atmosphere-Land System （FGOALS-s2） model. Our val- idation results show that the downscaled time series agree well with the present observed precipitation in terms of both the annual mean and the seasonal cycle. The regres- sion models built from the historical data are then used to generate future projections. The results show that the en- hanced land-sea thermal contrast strengthens both the subtropical anticyclone over the western Pacific and the east Asian summer monsoon flow under both RCPs. However, the trend of precipitation in response to warming over the 21 st century are different across eastern Chi- na under different RCPs. The area to the north of 32°N is likely to experience an increase in annual mean precipitation, while for the area between 23°N and 32°N mean precipitation is projected to decrease slightly over this century under RCP8.5. The change difference between scenarios mainly exists in the middle and late century. The land-sea thermal contrast and the associated east Asian summer monsoon flow are stronger, such that precipitation increases more, at higher latitudes under RCP8.5 compared to under RCP4.5. For the region south of 32°N, rainfall is projected to increase slightly under RCP4.5 but decrease under RCP8.5 in the late century. At the high resolution of 5 km, our statistically downscaled results for projected precipitation can be used to force hydrological models to project hydrological processes, which will be of great benefit to regional water planning and management.     

Effect of Decadal Changes in Air-Sea Interaction on the Climate Mean State over the Tropical Pacific

Collaboration of interannual variabilities and the climate mean state determines the type of E1 Nifio. Recent studies highlight the impact of a La Nifia-like mean state change, which acts to suppress the convection and low-level convergence over the central Pacific, on the predominance of central Pacific （CP） E1 Nifio in the most recent decade. However, how interannual variabilities affect the climate mean state has been less thoroughly investigated. Using a linear shallow-water model, the ef- fect of decadal changes of air-sea interaction on the two types of El Nifio and the climate mean state over the tropical Pacific is examined. It is demonstrated that the predominance of the eastem Pacific （EP） and CP E1 Nino is dominated mainly by relationships between anomalous wind stresses and sea surface temperature （SST）. Furthermore, changes between air-sea interactions from 1980-98 to 1999-2011 prompted the generation of the La Ninalike pattern, which is similar to the background change in the most recent decade.     

EMD方法在广西夏季降水量预测中的应用

对广西夏季降水量进行EMD分解后,利用均生函数相关法,比较不同IMF分量组合建模的预测,不同组合试验预测显示,用前二个IMF分量组合建模预测是最佳的组合方案。经对2001—2010年共10年广西夏季降水量实际预测检验表明,趋势预测准确率达70%以上,对夏季降水量预测较有参考价值。为基层台站的气候预测及服务提供一个客观预测方法。     

GNSS对流层水汽监测研究进展与展望EI北大核心CSCD

对流层是近地空间环境中与人类活动联系最为密切的大气层,而水汽是低层大气圈中最重要的组成部分之一。尽管水汽在对流层中所占比例较小,但在一系列天气和多种气候变化中都扮演着重要角色。随着全球导航卫星系统(GNSS)的快速发展,GNSS对流层水汽监测成为重要的研究和应用方向。本文系统介绍了GNSS多维水汽监测及其在相关方面应用的研究现状和进展。GNSS水汽监测研究方面,当前主要集中在二维大气可降水量监测和三维湿折射率/水汽密度廓线反演两部分;GNSS水汽应用研究方面,当前主要包括定位、短临降雨及旱涝监测、数值同化预报等。     

柴河水库防洪安全实时监控系统多年平均防洪效益计算

柴河水库工程管理向自动化、智能化发展,实现柴河流域防洪安全实时监控创造了显著的防洪效益。系统的多年平均防洪效益计算分两部分,即实际年平均效益和期望年平均效益,从实际和预期2个角度,采用实际发生年法和长系列调节法,计算了柴河水库防洪安全实时监控系统多年平均防洪效益。经过分析计算,系统的多年平均防洪效益的实际发生值为2982万元,系统的多年平均防洪效益的期望发生值为820万元。从“实际发生”和“预期”两个方面分别计算柴河水库防洪安全实时监控系统的效益,可以更全面地衡量系统的性价比。     

探测站点平均站间距计算公式的导出

通过对正三角形(等边三角形)、正方形和正六边形的镶嵌分析,推导出这3种网格图形自镶嵌时的平均站间距公式,得出只有用正六边形进行镶嵌所得出的平均站间距才具有可比性,建议其成为计算平均站间距的推荐公式。